Beans Boost Conception Rates

“I've been feeding whole soybeans to my cows for the past few years; starting before calving begins, for about 45 days,” says Jim Brinkley, Angus producer in Sullivan County, MO. “We've noticed a boost in conception and pregnancy rates from feeding just 3.5 lbs. of raw beans per cow per day.”

Brinkley got the idea of feeding whole beans to beef brood cows from research conducted by Chris Zumbrunnen, Extension livestock specialist; Monty Kerley, beef nutritionist; and David Patterson, beef reproductive physiologist — all of the University of Missouri.

“A few years back, I read a short report in BEEF magazine about research with safflower seed fed to late-gestating beef cows, with a significant increase in conception rates,” says Zumbrunnen. “Could we increase conception and calving rates in northern Missouri and Iowa by feeding whole soybeans?”

The Missouri researchers found the answer to be “yes,” but had to work on the timing a bit. Most response came from feeding 3.5 lbs. of whole soybeans per head daily, starting 45 days prior to the beginning of calving and ending when the cow calved.

That regimen resulted in 76% conception on the first service (breeding), and an overall pregnancy rate of 93%. By comparison, feeding combinations of corn gluten and soybean meal resulted in conception rates in the 50-62% range.

“Soybeans contain a fairly high level of polyunsaturated fatty acids (such as linoleic acid) that is used to synthesize prostaglandins, which in turn initiate and maintain the reproductive process,” notes Zumbrunnen. “We should mention that females in our studies were spring-calving cows in good condition, with average body condition scores of about six.”

Since Jim Brinkley feeds all of his cows soybeans, he doesn't have a control group for comparison, but he estimates about a 20% improvement in conception rates.

“We synchronize heats and breed all cows by A.I. (artificial insemination),” he says. “My cows are in good body condition at breeding time.”

Some producers are concerned that feeding whole soybeans (fat is the most concentrated source of energy) in late gestation might produce calves that are too heavy at birth, with attendant calving problems.

“In our projects, we have seen a slight increase in calf birth weight,” says Zumbrunnen. “But there has been no increase in calving difficulty as a result of this increased birth weight.”

Here's how beef specialists answer other questions:

Q. Aren't raw soybeans toxic to cattle?

A. Overfeeding soybeans can be toxic, but at 3-3.5 lbs. per cow per day, whole soybeans are as safe as feeding low levels of any grain.

Q. Don't soybeans need to be processed into meal or extruded before you feed them?

A. Not for cattle. For swine, soybeans must be processed or heated to destroy the trypsin-inhibiting agent, but this is not a problem in cattle.

Q. Aren't soybeans too expensive to feed?

A. Over the past four winters of feeding whole beans to cattle, the cost per cow per day has ranged between 25 to 29¢. “Soybeans here now are just over $5/bu.,” says Brinkley. “That makes the cost under 9¢/lb.”

Q. Can I feed twice as many beans every other day and still get the same result?

A. “I can't answer this for sure, but normally about 5% fat is about as high as you want to go in a beef cow's diet,” says Zumbrunnen. “Above that level, you run the risk of nutritional scours. Adding 3.5 lbs. of soybeans to a grass or hay diet gives a dietary fat content of about 5%. I'd be concerned about going much higher than that in one day.”

Q. What kind of facilities do I need to feed whole soybeans?

A. “I don't use bunks or troughs at all,” says Brinkley. “I pour the beans right on the grass and scatter them out so all the cows can get to them.”

Q. Can I feed lower quality beans and still get a good conception response?

A. You can feed small-seeded “BB” soybeans that would incur a market discount and still get the same response. You might not want to feed beans that are badly cracked or moldy. “Although last year I fed damaged soybeans that had been under flood and I couldn't see any difference in the pregnancy rate,” says Brinkley.

“We have consistently seen a 14-23% boost in first-service conception rate by feeding 3-3.5 lbs. of whole soybeans per cow for 30-45 days before calving,” Zumbrunnen says. “Raw soybeans are a safe, effective way to economically supplement beef brood cows.”